World Trade Centre - New
York - Some Engineering Aspects -- The University of Sydney - Department
of Civil Engineering
An in-depth look at why the towers collapsed. Many photos of the smoke and dust.
"[Henry H. Deutch, assistant to the chief structural engineer for construction manager Tishman Realty & Construction Co. Inc., New York City, during the construction of the WTC and currently head of HHD Consultants Inc., Osceola County, Fla.] says that originally, the north tower contained asbestos in its cementitious fireproofing as did the first 30 stories of the south tower. He believes the asbestos, which had been encapsulated, was removed after the 1993 bombing. In a press conference, Mayor Rudolph W. Giuliani said the city's health department had tested the air in the area and found no undue amount of chemical agents...The attacks were witnessed by hundreds of people in each of the locales. [Robert S. Vecchio, principal of metallurgical engineer Lucius Pitkin Inc.], who was part of the investigation of the 1993 bombing of the WTC, was an eyewitness to the Manhattan debacle from Pitkin's office about 1-2 mile north of the trade center. "The explosions were so tremendous," he says. "You could smell the jet fuel in the air."